/*
 * Copyright (c) 1999, 2003, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package javax.sound.sampled;

/**
 * A <code>EnumControl</code> provides control over a set of
 * discrete possible values, each represented by an object.  In a
 * graphical user interface, such a control might be represented
 * by a set of buttons, each of which chooses one value or setting.  For
 * example, a reverb control might provide several preset reverberation
 * settings, instead of providing continuously adjustable parameters
 * of the sort that would be represented by <code>{@link FloatControl}</code>
 * objects.
 * <p>
 * Controls that provide a choice between only two settings can often be implemented
 * instead as a <code>{@link BooleanControl}</code>, and controls that provide
 * a set of values along some quantifiable dimension might be implemented
 * instead as a <code>FloatControl</code> with a coarse resolution.
 * However, a key feature of <code>EnumControl</code> is that the returned values
 * are arbitrary objects, rather than numerical or boolean values.  This means that each
 * returned object can provide further information.  As an example, the settings
 * of a <code>{@link EnumControl.Type#REVERB REVERB}</code> control are instances of
 * <code>{@link ReverbType}</code> that can be queried for the parameter values
 * used for each setting.
 *
 * @author Kara Kytle
 * @since 1.3
 */
public abstract class EnumControl extends Control {

  // TYPE DEFINES

  // INSTANCE VARIABLES


  /**
   * The set of possible values.
   */
  private Object[] values;


  /**
   * The current value.
   */
  private Object value;

  // CONSTRUCTORS


  /**
   * Constructs a new enumerated control object with the given parameters.
   *
   * @param type the type of control represented this enumerated control object
   * @param values the set of possible values for the control
   * @param value the initial control value
   */
  protected EnumControl(Type type, Object[] values, Object value) {

    super(type);

    this.values = values;
    this.value = value;
  }

  // METHODS


  /**
   * Sets the current value for the control.  The default implementation
   * simply sets the value as indicated.  If the value indicated is not
   * supported, an IllegalArgumentException is thrown.
   * Some controls require that their line be open before they can be affected
   * by setting a value.
   *
   * @param value the desired new value
   * @throws IllegalArgumentException if the value indicated does not fall within the allowable
   * range
   */
  public void setValue(Object value) {
    if (!isValueSupported(value)) {
      throw new IllegalArgumentException("Requested value " + value + " is not supported.");
    }

    this.value = value;
  }


  /**
   * Obtains this control's current value.
   *
   * @return the current value
   */
  public Object getValue() {
    return value;
  }


  /**
   * Returns the set of possible values for this control.
   *
   * @return the set of possible values
   */
  public Object[] getValues() {

    Object[] localArray = new Object[values.length];

    for (int i = 0; i < values.length; i++) {
      localArray[i] = values[i];
    }

    return localArray;
  }


  /**
   * Indicates whether the value specified is supported.
   *
   * @param value the value for which support is queried
   * @return <code>true</code> if the value is supported, otherwise <code>false</code>
   */
  private boolean isValueSupported(Object value) {

    for (int i = 0; i < values.length; i++) {
      //$$fb 2001-07-20: Fix for bug 4400392: setValue() in ReverbControl always throws Exception
      //if (values.equals(values[i])) {
      if (value.equals(values[i])) {
        return true;
      }
    }

    return false;
  }

  // ABSTRACT METHOD IMPLEMENTATIONS: CONTROL


  /**
   * Provides a string representation of the control.
   *
   * @return a string description
   */
  public String toString() {
    return new String(getType() + " with current value: " + getValue());
  }

  // INNER CLASSES


  /**
   * An instance of the <code>EnumControl.Type</code> inner class identifies one kind of
   * enumerated control.  Static instances are provided for the
   * common types.
   *
   * @author Kara Kytle
   * @see EnumControl
   * @since 1.3
   */
  public static class Type extends Control.Type {

    // TYPE DEFINES

    /**
     * Represents a control over a set of possible reverberation settings.
     * Each reverberation setting is described by an instance of the
     * {@link ReverbType} class.  (To access these settings,
     * invoke <code>{@link EnumControl#getValues}</code> on an
     * enumerated control of type <code>REVERB</code>.)
     */
    public static final Type REVERB = new Type("Reverb");

    // CONSTRUCTOR


    /**
     * Constructs a new enumerated control type.
     *
     * @param name the name of the new enumerated control type
     */
    protected Type(String name) {
      super(name);
    }
  } // class Type

} // class EnumControl
